In motor vehicles that are able to be driven by a plurality of drive units, such as hybrid vehicles, the plurality of drive units may be positioned in a power train and be able to be coupled to one another using couplings. The coupling is opened or closed, depending on the type of operation of the vehicle.
Especially in the case of hydraulic couplings, based on malfunctions, it may happen that the coupling disks are not totally separated from each other in the open state, and a torque is transmitted. If the two coupling disks rotate at different speeds, this may lead to a grinding of the coupling disks, which causes them to wear. In addition, frictional heat is created, which may destroy the coupling and further components situated on it.
It would therefore be desirable to detect a malfunction of the coupling, particularly a malfunction which is able to lead to the further destruction of components.